1. Field of the Invention
The present invention relates to an automatic preparation apparatus for automatically performing preparation steps such as dissolution, extraction, filtration, dilution and reaction with reagent of a sample liquid.
2. Description of the Related Art
When a sample is injected into a component analysis system for component analysis, suspended matter contained in the sample is usually removed previously to dilute it to a predetermined concentration.
A centrifugal separator or a disposable filter is used for removing the suspended matter from the sample, while a measuring pipette is used for diluting the sample.
For example, when a liquid chromatography system is used for component analysis, neither of the above-mentioned means for removing and diluting the suspended matter can directly be coupled with the liquid chromatography system for operational reasons and thus the prepared sample is set to an automatic sampler or supplied to an injector by means of a microsyringe. Consequently, the liquid chromatography system cannot be operated fully automatically from preparation to analysis of the sample, and the preparation steps of the sample are currently being carried out manually.
However, if the preparation is carried out manually, there are disadvantages including a vast amount of treatment time required, as well as the possible occurrence of treatment error and contamination of the sample. Another disadvantage is that the preparation and component analysis by the liquid chromatography system cannot automatically be controlled in an interlocked manner.
To solve those disadvantages, the present applicant has proposed an automatic preparation apparatus which can mount a plurality of test tubes radially on a turntable, uses a filter robot for moving a detachable filter to above one of those test tubes and a probe robot for sampling a predetermined amount of a liquid from each test tube and injecting a predetermined amount of a liquid into each test tube and filter, and which can perform a desired preparation process by controlling the turntable, filter robot and probe robot in accordance with a predetermined sequence (U.S. Pat. No. 4,951,513).
However, according to the above-mentioned automatic preparation apparatus, the number and capacity of test tubes mountable on the turntable is limited, so that it is difficult to perform automatic preparation using a necessary number of large-capacity sample containers. If the area of the turntable is increased, the number and the capacity of containers can be increased, which, however, results in a considerable increase in the size of the whole apparatus, so that such a large apparatus is inconvenient for installation in laboratories or the like.